- Yhc - Haskell.org

Bytecode API library
by Robert Dockins 20 Jun '06

20 Jun '06

Friends! I have just released an alpha version of a library for reading and writing the YHC bytecode file format. It's not quite finished but currently quite usable. It reads and writes the entire bytecode set, version 1.9 (the one used by recent YHC builds). The project homepage is: http://www.eecs.tufts.edu/~rdocki01/yhc-bytecode.html From this page you can find tarballs, docs, and a darcs repository. Comments and suggestsions are welcome. Note that this library is currently GPL. I'm still considering my options on this front. If you have a strong opinion AND a convincing argument for some other license, email me. Thanks, and enjoy. -- Rob Dockins Talk softly and drive a Sherman tank. Laugh hard, it's a long way to the bank. -- TMBG

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Unknown preprocessor directive
by Andrew Wilkinson 09 Jun '06

09 Jun '06

Hi all, Work on getting YHC to compile under Windows is progressing well. Can someone suggest a reason why I get the following error when trying to build the YHC library? inst\bin\yhc.exe -i src/packages/yhc-base-1.0/ -d src/packages/yhc-base-1.0/ -c src\packages\yhc-base-1.0\Foreign\Word.hs yhc.exe: Unknown preprocessor directive at line 16 in file "D:\\programming\\yhc-devel/src\\packages\\yhc-base-1.0\\Foreign\\Word.hs" define WORD_TYPE(T,BS,LB,UB) \ Cheers, Andrew

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Libffi
by Andrew Wilkinson 08 Jun '06

08 Jun '06

Hi, I've recently been working on the scons build system for YHC. You'll probably have seen the various patches appear in darcs recently :-) It currently builds successfully on my machine, although there is still plenty of work to be done especially with regard to the installation. I'm trying to make the same build scripts work on Windows so we only need to maintain a single build system rather than different ones for different platforms, and we get away from the nasty autoconf/automake hackery. I've hit the problem that libffi currently does not compile using MSVC. Apparently the people who made the (rather wonderful) ctypes extension for Python have done some clever stuff and made it work, but as far as I can tell there is no release where this will work as yet. I have two questions: 1. Does anyone know where I can get windows-compatiable release of YHC (source code would be fine) 2. Is libffi optional for YHC, or is it required? Cheers, Andrew

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Build problems concerning FFI
by Leon Smith 02 Jun '06

02 Jun '06

Hello all. I'm the student working on the typechecker for Google's SoC. I ran into a few build problems with the repository. I've attached a patch for them, though two problems are not covered in this patch. These problems both concern yhc-devel/src/runtime/libtool which is a generated script. First, something tries to run it directly, without running sh on it. Second, the configuration script does not set the variable $max_cmd_len on my platform (Darwin). Both these cause the build process to fail. I worked around these issues by setting the executable bit and editing the generated script myself to set the variable. However the true fixes are beyond my expertise. Congrats on self hosting. I did download and try out YHC sometime in January. It compiled without problems, but I didn't get to use it. I don't remember what issues I was having with YHC and the program I was writing at the time. Best Wishes, Leon

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CAF vs 0-arity function question
by Robert Dockins 12 May '06

12 May '06

The HBC bytecode format has different constant tags for the folloing: 1) CAF, tag 'A' 2) 0-arity function, tag '0' http://haskell.org/haskellwiki/Yhc/RTS/hbc Why the distinction? Maybe I don't fully understand, but I thought that a 0-arity function _was_ a CAF? The runtime seems to treat them very much the same (although I can't be quite sure -- reading C gives me a headache ;) Rob Dockins

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Haskell.org and Google Summer of Code 2006
by Paolo Martini 25 Apr '06

25 Apr '06

Hello, It is now official. Haskell.org is a mentoring organization for this year's Summer of Code programme. You can see it listed on the official site <http://code.google.com/soc/> clicking on `Haskell.org (ideas)' you'll be directed to the trac site we are setting up. (It's 4 AM and I've just finished adding the projects, and cleaning things up a bit.) I am _very_ happy about seeing this project working out for real. I fear that I wouldn't be able to reach everybody even mailing all the important mailing list; I hope many students will be able to take advantage of this great occasion. Help me spread the word, tell everybody about the project :-) You can find the new site here <http://hackage.haskell.org/trac/summer-of-code/>, the StartPage will be updated with details during the program. Projects ideas and volunteers for mentoring are still very much welcome! students' application period starts on May 1. Thanks very much for the support, hope to hear thoughts and proposals, Paolo. --

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Google Summer of Code 2006
by Paolo Martini 24 Apr '06

24 Apr '06

Hello, Haskell.org is going to partecipate as mentoring organization to the Google Summer of Code programme of this year. We have formed a group of volunteers taking care of the administrative work as well as the mentoring part. The group is listed here: <http://haskell.org/haskellwiki/Summer_of_Code:_People>. We are now looking for projects, and mentors. We've reached number 24 but we are happily going to add more, Haskell Open Source paid work for the summer! If you run some active open source program you might want to mentor some student who will be working on your code, for example. Either just add your ideas here: <http://haskell.org/haskellwiki/Summer_of_Code:_Project_suggestions> (as well as your informations on the People's page) or contact me for details. I am also looking for students, I'd like to ear from them if they are going to partecipate with Haskell projects, last year I was alone! (I did write the bindings to the Cairo vector graphics library and integrated them in Gtk2Hs.) Details about the programme itself can be found on the official webpage: http://code.google.com/summerofcode.html Hoping you like the idea as much as me, Paolo. --

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Bytecode module interface
by Robert Dockins 15 Apr '06

15 Apr '06

Hello all, I'm interested in doing some YHC bytecode manipulation, and I'd like to be able to read a bytecode module using Haskell. In the online Haddock docs, there's a lovely-looking module named 'Module' which contains readModule :: String -> Module http://www-users.cs.york.ac.uk/~ndm/yhc/docs/Module.html However, 'Module' doesnt appear in the 'yhc' or 'yhc-devel' repositories. Does this code exist somewhere else? How can I get at it? Thanks Rob Dockins

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YHC .NET backend
by Oliver J Hunt 02 Apr '06

02 Apr '06

Does anyone know if there are any papers available on how the Yhc .NET back end works? I've looked briefly at the codegen and output and as far as I can make out it is performing complete type erasure and converting everything to (effectively) typeless closures. Does anyone know if this is what is going on, or am i missing something entirely? Cheers, Oliver

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Re: [Yhc] Patch: 'Fix reading from past the end of G_markTable in mkt_firstMarked ()'
by Tom Shackell 27 Mar '06

27 Mar '06

Hi Michal, Oh okay, the constant table is a table of constants that are used by a function. For example when a MK_AP is performed it says which function to make an application to by using an index into the constant table. These have to be malloced because you don't know what's in them, or how big they need to be, until the bytecode is loaded. However, a function can indeed have no constants (although it's fairly uncommon). Easiest way is just to add a check before that malloc. Thanks Tom Michał Pałka wrote: > Neil, > > Attached. I think they are 'sometimes zero'. I hope the stack trace > makes it clear to you what happens, as it's almost clear to me. > > This looks like allocating ConstTable of size 0. But what is ConstTable > anyway (are we allocating constants in tables - why?)? > > I'm not telling that calling malloc (0) is inherently bad. As you can > see, malloc allows this. Electric Fence bails out when it sees malloc > (0), but this particular check could be turned off. It all depends on > your policy, whether you allow 0-mallocs or not. > > A heavy-weight approach to sorting this out came to my mind. You define: > void* zmalloc (size_t n) > { > if (n != 0) return malloc (n); > return NULL; > } > > void* nzmalloc (size_t n) > { > assert (n != 0); > return malloc (n); > } > And use one of them depending on what you expect n to be. But wrapping > some mallocs in if (n != 0) {} is also ok IMO. > > Thanks, > Michal > > On Tue, 2006-03-21 at 14:30 +0000, Neil Mitchell wrote: > >>Hi Michal, >> >>Any chance you can send an example of one of these 0-sized mallocs? >>Are they always zero, normally zero or what? >> >>In general though, it would be nice to have Yhc work perfectly (i.e. >>no warnings) with these tools, so its easier to detect real problems, >>so I'd have thought the answer was yes, these need fixing. >> >>Thanks >> >>Neil >> >>On 3/20/06, Michał Pałka <michal.palka(a)poczta.fm> wrote: >> >>>I discovered this using Valgrind and Electric Fence. There are also >>>mallocs of size 0 that are considered errors by efence. Should I attempt >>>to fix them? >>> >>>Michal >>> >>> >>>_______________________________________________ >>>Yhc mailing list >>>Yhc(a)haskell.org >>>http://haskell.org/mailman/listinfo/yhc >>> >>> >>> >>> >>> >>> >>>------------------------------------------------------------------------ >>> >>>#0 0x00002aaaab1d0189 in kill () from /lib/libc.so.6 >>>#1 0x00002aaaaabc5053 in EF_Abort () from /usr/lib/libefence.so.0.0 >>>#2 0x00002aaaaabc4c04 in memalign () from /usr/lib/libefence.so.0.0 >>>#3 0x00002aaaaabc4c97 in malloc () from /usr/lib/libefence.so.0.0 >>>#4 0x0000000000402c98 in mod_loadConstTable (mod=0x2aaaab42efb8, finfo=0x2aaab0a12fb8) at module.c:272 >>>#5 0x0000000000403a4b in mod_loadFun (mod=0x2aaaab42efb8, name=0x2aaab0a14fe4 "Prelude.Num.Prelude.Int.-", obj=0x2aaab0a0cff0) >>> at module.c:439 >>>#6 0x0000000000403cb4 in mod_loadObject (mod=0x2aaaab42efb8, offs=117594, obj=0x2aaab0a0cff0) at module.c:514 >>>#7 0x0000000000402a13 in mod_resolve (module=0x2aaab0a0eff8 "Prelude", item=0x2aaab0a10fe4 "Prelude.Num.Prelude.Int.-") at module.c:209 >>>#8 0x0000000000402f0d in mod_loadConstTable (mod=0x2aaab089cfb8, finfo=0x2aaab0997fb8) at module.c:322 >>>#9 0x0000000000403a4b in mod_loadFun (mod=0x2aaab089cfb8, name=0x2aaab0999ff8 "valid", obj=0x2aaab0991ff0) at module.c:439 >>>#10 0x0000000000403cb4 in mod_loadObject (mod=0x2aaab089cfb8, offs=1475, obj=0x2aaab0991ff0) at module.c:514 >>>#11 0x0000000000402a13 in mod_resolve (module=0x2aaab0993ff8 "Main", item=0x2aaab0995ff8 "valid") at module.c:209 >>>#12 0x0000000000402f0d in mod_loadConstTable (mod=0x2aaab089cfb8, finfo=0x2aaab0989fb8) at module.c:322 >>>#13 0x0000000000403a4b in mod_loadFun (mod=0x2aaab089cfb8, name=0x2aaab098bff8 "queens", obj=0x2aaab0983ff0) at module.c:439 >>>#14 0x0000000000403cb4 in mod_loadObject (mod=0x2aaab089cfb8, offs=1580, obj=0x2aaab0983ff0) at module.c:514 >>>#15 0x0000000000402a13 in mod_resolve (module=0x2aaab0985ff8 "Main", item=0x2aaab0987ff8 "queens") at module.c:209 >>>#16 0x0000000000402f0d in mod_loadConstTable (mod=0x2aaab089cfb8, finfo=0x2aaab097bfb8) at module.c:322 >>>#17 0x0000000000403a4b in mod_loadFun (mod=0x2aaab089cfb8, name=0x2aaab097dff8 "main", obj=0x2aaab0979ff0) at module.c:439 >>>#18 0x0000000000403cb4 in mod_loadObject (mod=0x2aaab089cfb8, offs=1606, obj=0x2aaab0979ff0) at module.c:514 >>>#19 0x0000000000402a13 in mod_resolve (module=0x7fffffecab6c "Main", item=0x41f1b1 "main") at module.c:209 >>>#20 0x00000000004046ee in initGlobals (mainMod=0x7fffffecab6c "Main", mainFunc=0x7fffffec9708, _toplevel=0x7fffffec9710, >>> _driver=0x7fffffec9700) at main.c:120 >>>#21 0x0000000000404880 in init (mainMod=0x7fffffecab6c "Main", mainFunc=0x7fffffec9708, _toplevel=0x7fffffec9710, _driver=0x7fffffec9700) >>> at main.c:145 >>>#22 0x00000000004048de in main (argc=2, argv=0x7fffffec9808) at main.c:171

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